JP7243606B2 - Method for manufacturing display device, method for transferring chip component, and radiation-sensitive composition - Google Patents

Description

The present invention relates to a display device manufacturing method, a chip component transfer method, and a radiation-sensitive composition.

Micro LED displays are attracting attention as next-generation display devices. A micro LED display is a display device in which each pixel is a fine light-emitting diode (hereinafter referred to as LED) chip, and these LED chips are densely spread over the surface of a display substrate. In manufacturing such a micro LED display, it is important to accurately and reliably arrange the LED chips on the surface of the display substrate.

As a transfer technique for transporting chip components and arranging them on the substrate surface, for example, a technique using a transfer tool disclosed in Patent Document 1 is known. The transfer tool includes an electrostatic transfer head array that captures chip components. In the actual manufacture of micro LED displays, there is a demand for a method of transferring LED chips, which are electronic components, with less influence such as electrostatic breakdown.

As such an LED chip transfer method, a method including the following steps (1) to (4) has been proposed.
(1) First, a large number of LED chips are arranged on the temporary substrate side adhesive layer provided on the surface of the temporary substrate (tray).
(2) Next, after the LED chips are attached to the transfer adhesive layer provided on the surface of the transfer plate, the transfer plate is lifted. As a result, the LED chip is separated from the temporary substrate-side adhesive layer of the temporary substrate. That is, the LED chip moves (is transferred) from the temporary substrate side to the transfer plate side.
(3) Next, a TFT (Thin Film Transistor) substrate is prepared. An anisotropic conductive film is placed on the surface of the TFT substrate on which the LED chips are mounted. After the transfer plate is arranged so as to face the TFT substrate, the transfer plate and the TFT substrate are brought close to each other so that the LED chips are brought into contact with the anisotropic conductive film.
(4) Thereafter, the transfer plate and the TFT substrate are sandwiched and thermocompressed to connect the LED chips to the drive circuit on the TFT substrate side, and then the transfer adhesive layer of the transfer plate is peeled off from the LED chips. . In this step, the LED chips are transferred from the transfer board to the drive circuit board.

Japanese Patent Application Publication No. 2015-529400

In the above method of transferring the LED chip, if the adhesive strength between the transfer adhesive layer and the LED chip is weak, the LED chip will fall during transfer and the yield will not increase. There is a problem that it takes time to transfer to the circuit board.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing a display device capable of reliably transferring a chip component to a desired position on a drive circuit board and having a high yield. . SUMMARY OF THE INVENTION It is an object of the present invention to provide a transfer method capable of reliably transferring a chip component to a desired position on a drive circuit board. Another object of the present invention is to provide a radiation-sensitive composition that can reliably transfer chip components.

In order to solve the above-described problems and achieve the object, the first aspect of the present invention is
a first substrate on which chip parts constituting pixels are arranged; and a second substrate having an organic layer formed of a radiation-sensitive composition containing a compound having a polymerizable group and a radical polymerization initiator, contacting a chip component on a substrate with an organic layer on the second substrate and bonding them by exposure; separating the chip component from the first substrate and transferring the chip component to the second substrate; a third substrate having an electrode thereon and a conductive layer formed so as to cover the electrode; bringing the chip part on the second substrate into contact with the conductive layer of the third substrate and heating the chip component; and a step of separating the second substrate and the third substrate and transferring the chip component to the third substrate.

（式（１）中、Ｒ^ａは水素原子またはメチル基を示す。R^ｂからR^ｄは,それぞれ独立に、水素原子、炭素数１から１２の炭化水素基、炭素数１から１２アルコキシル基、炭素数１から１２のハロゲン化アルキルを示す。ｎは１から１２の整数である。＊は結合位を示す。） In the first aspect, the compound having a polymerizable group is preferably a compound having a structural site represented by the following formula (1).

(In Formula (1), R ^a represents a hydrogen atom or a methyl group; R ^b to R ^d each independently represent a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, represents an alkyl halide having 1 to 12 carbon atoms, n is an integer of 1 to 12. * represents a bonding position.)

In the first aspect, the content of the organic solvent contained in the radiation-sensitive composition is preferably 3% by mass or less.

In the first aspect, the chip component is preferably a micro LED chip.

A second aspect of the present invention is a method for transferring a chip, comprising: a first substrate on which chip parts constituting pixels are arranged; and a radiation-sensitive composition containing a compound having a polymerizable group and a radical polymerization initiator. a second substrate having an organic layer formed by a chip component on the second substrate, comprising a step of separating from the substrate and transferring to the second substrate; and a third substrate having one or more electrodes provided thereon and a conductive layer formed over the electrodes. , the step of contacting the conductive layer of the third substrate and heating, and the step of separating the second substrate and the third substrate and transferring the chip component to the third substrate. is the relocation method.

In the second aspect, it is preferable that the transfer member layer formed of the radiation-sensitive composition is adhered to the chip component by exposure and detached from the chip component by heating.

（式（１）中、Ｒ^ａは水素原子またはメチル基を示す。Ｒ^ｂからＲ^ｅは,それぞれ独立に、水素原子、炭素数１から１２の炭化水素基、炭素数１から１２アルコキシル基、炭素数１から１２のハロゲン化アルキルを示す。ｎは１から１２の整数である。＊は結合位を示す。） A third aspect of the present invention is a radiation-sensitive composition containing a compound having a polymerizable group represented by the following formula (1), a radical polymerization initiator, and a thermal acid generator.

(In formula (1), R ^a represents a hydrogen atom or a methyl group. R ^b to R ^e each independently represent a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, represents an alkyl halide having 1 to 12 carbon atoms, n is an integer of 1 to 12. * represents a bonding position.)

According to the method of manufacturing a display device according to the present invention, a method of manufacturing a display device can be realized in which a chip component is easily transferred to a desired position on a drive circuit board by heat treatment, and the manufacturing yield is high. According to the transfer method of the chip component according to the present invention, it is possible to realize a transfer method that can reliably transfer the chip component to a desired position on the drive circuit board by heat treatment. According to the radiation-sensitive composition material according to the present invention, chip parts can be bonded by exposure, and relocation can be easily performed by heat treatment.

FIG. 1 is a process cross-sectional explanatory view showing a state in which a temporary substrate, which is a first substrate, and a substrate for transfer, which is a second substrate, are opposed to each other in a manufacturing method of a display device according to an embodiment of the present invention. FIG. 2 shows a state in which the organic layer of the transfer substrate, which is the second substrate, is adhered to the upper surface of the chip component on the side of the temporary substrate, which is the first substrate, in the manufacturing method of the display device according to the embodiment of the present invention. It is process cross-sectional explanatory drawing which shows. FIG. 3 shows, in the manufacturing method of the display device according to the embodiment of the present invention, after the organic layer of the transfer substrate, which is the second substrate, is adhered to the top surface of the chip component on the side of the temporary substrate, which is the first substrate, It is process cross-sectional explanatory drawing which shows the state which separated the 2nd board|substrate and the 1st board|substrate, and moved the chip component to the board|substrate side for a transfer. FIG. 4 is a process cross-sectional explanatory view showing a state in which a transfer substrate to which chip components have been transferred and a driving circuit substrate, which is a third substrate, are opposed to each other in the manufacturing method of the display device according to the embodiment of the present invention. is. FIG. 5 is a process cross-sectional explanatory view showing a state in which the chip component transferred to the transfer substrate and the drive circuit board, which is the third substrate, are opposed to each other in the manufacturing method of the display device according to the embodiment of the present invention. is. FIG. 6 shows a step of bringing the chip component on the second substrate and the conductive layer on the third substrate into contact with each other and bonding them while heating in the manufacturing method of the display device according to the embodiment of the present invention. It is cross-sectional explanatory drawing. FIG. 7 shows that, in the manufacturing method of the display device according to the embodiment of the present invention, after the transfer substrate and the drive circuit substrate are overlapped and adhered while being heated, the organic layer on the transfer substrate is thermally decomposed and adhered. It is process cross-sectional explanatory drawing which shows the state which separated the chip component from the organic layer, and moved the chip component to the drive circuit board side by reducing force. FIG. 8 shows the results of comparing the adhesion of test pieces after photocuring and after heat treatment.

Details of the method for manufacturing a display device, the method for transferring chip parts, and the radiation-sensitive composition forming the organic layer according to the embodiment of the present invention will be described below. However, it should be noted that the drawings are schematic, and that the dimensions of each member, the ratio of dimensions, the shape, and the like are different from the actual ones. In addition, there are portions with different dimensional relationships, ratios, and shapes between the drawings.

A method of manufacturing a display device according to the present embodiment will be described below with reference to FIGS. 1 to 9. FIG. The present embodiment is a method of transferring a chip component and a method of manufacturing a display device to which an organic layer is applied according to the present invention. In this embodiment, a micro LED display is applied as the display device.

First, as shown in FIG. 1, a first substrate (hereinafter also referred to as temporary substrate 1) is prepared. The temporary substrate 1 is provided with an adhesive layer having a low adhesive strength on one substrate surface. A large number of chip components 2 are arranged on the temporary substrate 1 at predetermined intervals. Note that the chip component 2 used in the present embodiment is a micro LED chip that constitutes a pixel of a display device. On the surface of the temporary substrate 1, an arrangement area for arranging a large number of chip components 2 is set to have the same vertical and horizontal dimensions as the display area of the micro LED display.

In this embodiment, as shown in FIG. 1, the chip component is adhered to the temporary substrate 1 with an adhesive having a small adhesive strength.

Next, as shown in FIG. 1, a second substrate (hereinafter also referred to as transfer substrate 4) is prepared. The transfer substrate 4 is provided with an organic layer 3 along one substrate surface. The organic layer 3 is made of a radiation-sensitive composition containing a compound having a polymerizable group and a radical polymerization initiator. By exposing the organic layer 3 to ultraviolet light containing a wavelength of 365 nm, the organic layer 3 exhibits adhesion.
The radical polymerization initiator contained in the radiation-sensitive composition generates radicals, and advances the radical polymerization reaction of the compound having a polymerizable group, thereby developing adhesiveness. The adhesive strength of the organic layer 3 is sufficiently higher than that of the adhesive layer provided on the temporary substrate 1 side.

（式（１）中、Ｒ^ａは水素原子またはメチル基を示す。Ｒ^ｂからＲ^ｄは,それぞれ独立に、水素原子、炭素数１から１２の炭化水素基、炭素数１から１２アルコキシル基、炭素数１から１２のハロゲン化アルキルを示す。ｎは１から１２の整数である。＊は結合位を示す。） Here, the radiation sensitive composition will be explained. The radiation-sensitive composition of the present invention is a radiation-sensitive composition containing a compound having a polymerizable group and a radical polymerization initiator.
Examples of the polymerizable group include a (meth)acryloyl group, a vinyl group, and an epoxy group. A group having a structural moiety having a moiety is preferred.
is preferably a compound having

(In formula (1), R ^a represents a hydrogen atom or a methyl group. R ^b to R ^d each independently represent a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, represents an alkyl halide having 1 to 12 carbon atoms, n is an integer of 1 to 12. * represents a bonding position.)

式（２）中、Ｒ^１及びＲ^３は、それぞれ独立して、炭素数１～８の１級あるいは２級アルキル基であり、置換基として炭化水素基、フッ素化アルキル基あるいはケイ素化アルキル基を有していても良い。Ｒ^２及びＲ^４は、それぞれ独立して、炭素数１～８のアルキル基、またはアリール基であり、Ｒ^２及びＲ^４がアルキル基の場合には、置換基として炭化水素基、フッ素化アルキル基あるいはケイ素化アルキル基を有していても良い。Ｘは炭素数１から１２の２価の炭化水素基を表す。Ｒ^５は、重合性基を含む有機基を示す。Ｚはｍ価の有機基を表し、ｍは１から１０の整数を示す。 More specifically, the compound represented by the above formula (1) is a compound represented by the following formula (2).

In formula (2), R ¹ and R ³ are each independently a primary or secondary alkyl group having 1 to 8 carbon atoms, and a hydrocarbon group, a fluorinated alkyl group or a siliconized alkyl group as a substituent. may have R ² and R ⁴ are each independently an alkyl group having 1 to 8 carbon atoms or an aryl group, and when R ² and R ⁴ are an alkyl group, the substituents are a hydrocarbon group and a fluorinated alkyl or a siliconized alkyl group. X represents a divalent hydrocarbon group having 1 to 12 carbon atoms. ^R5 represents an organic group containing a polymerizable group. Z represents an m-valent organic group, and m represents an integer of 1 to 10.

R ¹ and R ³ are preferably both alkyl groups, more preferably methyl groups. R ⁷ and R ⁸ are preferably both hydrogen atoms. X preferably has 1 to 3 carbon atoms. Z is preferably a divalent to pentavalent organic group.

The reason why the compound of the present invention enables radiation-sensitive curable adhesion is that it has the above-described structural site ^R5 . By adding a radical polymerization initiator to the composition, a cross-linking reaction proceeds between the compounds, and curing shrinkage of the entire organic layer proceeds, whereby substrates can be bonded together.

In addition, the reason why the compound of the present invention can lower the adhesiveness by heating is that it has the above structural sites ^R1 , ^R2 , ^R3 and ^R4 . By adding a thermal acid generator to the composition, the acid generated after heating catalyzes the decomposition reaction of the ester in the above chemical formula (2) to decompose it into a carboxylic acid and an unsaturated hydrocarbon. As a result, part of the molecular structure is decomposed by heating, and the adhesiveness of the entire organic layer is remarkably lowered.

In addition, the reason why the compound of the present invention can be used as a solvent-free adhesive is that it has a low molecular weight and liquid properties compared to linear polymers, and despite its low molecular weight, it has a large number of crosslinkable properties in its structure. Since it has the structural part ^R5 , the crosslink density at the time of curing can be made extremely high.

The compound having a polymerizable group of the present invention can be synthesized by a thiol-ene reaction. It can be obtained by reacting a sulfur compound having multiple thiol groups with a compound having a functional group capable of reacting with thiol-ene.

Examples of sulfur compounds having multiple thiol groups are shown below.
The sulfur compound having a plurality of thiol groups is not particularly limited as long as it has a plurality of thiol groups and does not have a group that is decomposed by an alkaline aqueous solution, but it has 2 to 5 thiol groups. It is preferably a compound having a molecular weight of 90 or more and 1000 or less because of ease of decomposition.

As the sulfur compound, both aliphatic and aromatic thiol compounds can be used, and there is no particular limitation. Specific examples of such polyfunctional thiol compounds include glycol dimercaptoacetate, trimethylolpropane tris (3-mercaptopropionate), trimethylolpropane tris (2-mercaptopropionate), trimethylol Propane tris (2-mercaptoacetate), pentaerythritol tetrakis (thioglycolate), pentaerythritol tetrakis (2-mercaptoacetate), allyl mercaptan, ethylene glycol dimercaptopropionate, trithiocyanuric acid (1,3,5-triazine- 2,4,6-trithiol), 3-dithiol phenyl ether, 1,3-dimethylthiomethylbenzene, pentaerythritol tetrakismercaptopropionate, 1,4-butanedithiol, 1,5-pentanedithiol, 1,6- pentanedithiol, tetramethylene glycol-bis-mercaptopropionate, 1,6-hexyldiol-bis-mercaptopropionate, pentaerythritol bismercaptopropionate, pentaerythritol trismercaptopropionate, trimethylolpropane bismercaptopropionate pionate, trimethylolpropane trismercaptopropionate, dipentaerythritol trismercaptopropionate, sorbitol trismercaptopropionate, sorbitol tetrakismercaptopropionate, sorbitol hexakismercaptopropionate, dithioethyl terephthalate, 1,6 -hexanediol dithioethyl ether, 1,5-pentanediol dithioethyl ether, and pentaerythritol-tetra-(β-thioethyl ether), 9,9-bis(4-mercaptophenyl)fluorene. One or more types are mentioned.

The thiol-ene-reactive functional groups of the present invention include (meth)acryloyl groups, terminal alkenes (vinyl groups, allyl groups, vinyloxy groups, allyloxy groups, etc.), and terminal alkynes. The number of functional groups is preferably two or more.

As mentioned above, the polymer to be used in the present invention includes the following compounds, but is not limited thereto.

ただし、上記式中のＸは下記式（４）で示される構造である。

However, X in the above formula is a structure represented by the following formula (4).

上記式（５）から（８）のＸは、上記式（４）で示される構造である。

X in the above formulas (5) to (8) is a structure represented by the above formula (4).

As the radical polymerization initiator preferably used in the present invention, for example, a radical polymerization initiator that generates the most radicals around 365 nm is used, and an acid generator that generates the most acid around 250 to 300 nm, which does not overlap around 365 nm. It can be used in combination with the use of agents. By using such a combination, radical cross-linking can be generated by exposure at an exposure wavelength of around 365 nm, and the resulting cured film is then exposed to light around 250-300 nm to promote the decomposition reaction by the generated acid. It becomes possible to

A radical polymerization initiator can initiate a cross-linking reaction of a compound having a polymerizable group upon exposure to radiation such as visible rays, ultraviolet rays, deep ultraviolet rays, electron beams, and X-rays.
Examples thereof include O-acyl oxime compounds, α-aminoketone compounds, α-hydroxyketone compounds, acylphosphine oxide compounds and the like.

Examples of O-acyloxime compounds include 1-[9-ethyl-6-(2-methylbenzoyl)-9. H. -carbazol-3-yl]-ethane-1-one oxime-O-acetate, 1-[9-ethyl-6-benzoyl-9. H. -carbazol-3-yl]-octan-1-one oxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9. H. -carbazol-3-yl]-ethan-1-one oxime-O-benzoate, 1-[9-n-butyl-6-(2-ethylbenzoyl)-9. H. -carbazol-3-yl]-ethan-1-one oxime-O-benzoate, ethanone, 1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylbenzoyl)-9. H. -carbazol-3-yl]-, 1-(O-acetyloxime), ethanone, 1-[9-ethyl-6-(2-methyl-4-tetrahydropyranylbenzoyl)-9. H. -carbazol-3-yl]-, 1-(O-acetyloxime), ethanone, 1-[9-ethyl-6-(2-methyl-5-tetrahydrofuranylbenzoyl)-9. H. -carbazol-3-yl]-,1-(O-acetyloxime), ethanone, 1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxolanyl)methoxy benzoyl}-9. H. -carbazol-3-yl]-, 1-(O-acetyloxime), ethanone, 1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylmethoxybenzoyl)-9. H. -carbazol-3-yl]-, 1-(O-acetyloxime), 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)] and the like.

Examples of α-aminoketone compounds include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4 -morpholin-4-yl-phenyl)-butan-1-one, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-(dimethylamino)-1-(4- morpholinophenyl)-2-benzyl-1-butanone, 1-[4-(2-hydroxyethylsulfanyl)phenyl]-2-methyl-2-(4-morpholino)propan-1-one and the like.

Methylpropan-1-one, 1-(4-i-propylphenyl)-2-hydroxy-2-methylpropan-1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexylphenyl ketone and the like.

Examples of acylphosphine oxide compounds include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

(B) The radiation-sensitive radical polymerization initiator is preferably an O-acyloxime compound, an α-aminoketone compound and an acylphosphine oxide compound, from the viewpoint of further accelerating the curing reaction by radiation. Aminoketone compounds are more preferred, and O-acyloxime compounds are even more preferred.

Examples of such radical polymerization initiators include O-acyloxime compounds, acetophenone compounds, acylphosphine oxide compounds and biimidazole compounds.
The content of the radical polymerization initiator of the present invention is 0.1 to 10 parts by mass, preferably 1 to 5 parts by mass, per 100 parts by mass of the compound having a polymerizable group. By using it in this range, it becomes possible to exhibit excellent adhesiveness.

≪Thermal acid generator≫
The acid generator of the present invention refers to a substance that generates an acid when heated in the range of 120°C to 250°C, and refers to a compound having an acid-dissociable group. The generated acid can dissociate the acid dissociable site. The acid-dissociable site includes an acetal bond site, an ester bond site, a urethane bond site, and the like.
The structural site (1) of the present invention has an acetal binding site, and is depolymerized by the acid generated from the thermal acid generator to decompose the structure. As such a decomposition reaction progresses in the organic layer, the adhesive force of the organic layer decreases. A substance that functions as a thermal acid generator may also function as a photoacid generator, and by using a wavelength different from that of the radical polymerization initiator described above, it can also be used as a photoacid generator. Two or more of such acid generators may be contained. Acid generators may be low molecular weight or high molecular weight.

As the thermal acid generator, known compounds can be used, such as onium salt compounds, N-sulfonyloxyimide compounds, sulfonimide compounds, halogen-containing compounds, diazoketone compounds and the like. these are,

Examples of onium salt compounds include sulfonium salts, tetrahydrothiophenium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts and the like.
Specific examples of the acid generator include compounds described in paragraphs [0080] to [0113] of JP-A-2009-134088 and paragraphs [0086] to [0140] of JP-A-2017-67966. is mentioned.

Examples of the acid generated from the thermal acid generator include sulfonic acid, imidic acid, amic acid, methide acid, phosphinic acid, carboxylic acid and the like. Among these, sulfonic acid, imidic acid, amic acid and methide acid are preferred.

The amount of the thermal acid generator used is preferably 1 part by mass, more preferably 5 parts by mass, and even more preferably 10 parts by mass with respect to 100 parts by mass of the compound having a polymerizable group.
By setting the content of the thermal acid generator within the above range, the adhesive force can be reduced.

≪Adhesion aid≫
The adhesion aid of the present invention is a component that improves the adhesiveness between a film forming object such as a substrate and a cured film. Adhesion aids are particularly useful for improving the adhesion between an inorganic substrate and a cured film. Examples of inorganic substances include silicon compounds such as silicon, silicon oxide, and silicon nitride, and metals such as gold, copper, and aluminum. Functional silane coupling agents are preferred. KAYAMER PM-21 (manufactured by Nippon Kayaku Co., Ltd., 2-methacryloyloxyethylcaproate acid phosphate) can be mentioned as a commercial product of such an adhesion aid.
The content of the adhesion aid is usually 30 parts by mass or less, preferably 0.5 to 20 parts by mass, preferably 1 to 100 parts by mass, relative to 100 parts by mass of the compound having a polymerizable group in the radiation-sensitive composition. 10 parts by mass is more preferable.

≪Surfactant≫
Examples of the surfactant of the present invention include fluorine-based surfactants and silicone-based surfactants. These surfactants may be used alone or in combination of two or more. As the surfactant, a surfactant described in JP-A-2011-18024 can be used.
The content of the surfactant is usually 3 parts by mass or less, preferably 0.01 to 2 parts by mass, and 0.01 to 2 parts by mass, per 100 parts by mass of the S compound and E compound in the radiation-sensitive composition. 05 to 1 part by mass is more preferable.

The radiation-sensitive composition of the present invention is solvent-free. However, it can be used as a solvent at 3% by mass or less in the radiation-sensitive composition. The solvent preferably dissolves the acid generator and the acid diffusion controller. Examples of specific solvents include alcohol solvents, ether solvents, ketone solvents, amide solvents, ester solvents, hydrocarbon solvents and the like.

Regarding the transfer method of chip parts,
The chip components 2 on the temporary substrate 1 are transferred using the transfer substrate 4 described above. As shown in FIG. 2, by bringing the transfer substrate 4 and the temporary substrate 1 close to each other, the organic layer 3 of the transfer substrate 4 is adhered to the upper surface of the chip component 2 on the temporary substrate 1 .
After that, as shown in FIG. 3, the transfer substrate 4 and the temporary substrate 1 are separated from each other to separate the chip component 2 from the temporary substrate side. Here, since the adhesive force of the organic layer 3 is significantly stronger than the adhesive force of the adhesive on the temporary substrate side, the chip component 2 is easily peeled off from the temporary substrate side.
In this manner, the chip component 2 is transferred from the temporary substrate 1 side to the transfer substrate 4 side. The transfer substrate 4 and the temporary substrate 1 can be moved closer to each other or separated from each other by moving the temporary substrate 1 with respect to the transfer substrate 4 or by moving the transfer substrate 4 with respect to the temporary substrate 1 . good.

Next, as shown in FIG. 4, a TFT (Thin Film Transistor) substrate 5 is prepared as a third substrate (also referred to as a drive circuit substrate or TFT substrate 5). A driving circuit (not shown) is formed on the TFT substrate 5 . An electrode 6 is provided on the TFT substrate 5 .
Chip component 2 is in contact with a conductive layer formed to cover electrode 6 on TFT substrate 5 . An anisotropically conductive film can be used for this conductive layer.

Next, as shown in FIG. 5, the transfer substrate 5 and the TFT substrate 6 are brought close to each other, and the chip component 2 is adhered to the conductive layer 3 . Then, the chip component 2 can be adhered to the transfer substrate 5 and the TFT substrate 6 under appropriate pressure and temperature conditions.

When an anisotropic conductive film is used, the conductive particles in the anisotropic conductive film are pressed together to form conductive regions. Therefore, the driving circuit side and the chip component 2 can be electrically connected.
This bonding can be performed by pressing while heating. The heating temperature is preferably in the range of 100°C to 250°C. By heating in this range, the acid is dissociated from the thermal acid generator contained in the organic layer 3, and the acid-dissociable sites are depolymerized, so that the thermal decomposition of the compound forming the organic layer 3 proceeds, The adhesion of layer 3 is reduced.
The reduced adhesiveness of the organic layer 3 makes it possible to separate the chip component 2 and the TFT substrate 6 easily, so that the chip component 2 can be transferred from the transfer substrate 4 to the TFT substrate 6 .

According to the manufacturing method of the display device according to the present embodiment, the chip component 2 can be reliably transferred to a desired position on the TFT substrate 6, and the precision of pixel arrangement of the micro LED display can be improved. Moreover, according to the manufacturing method of the display device according to the present embodiment, since the chip component 2 can be transferred successfully, the manufacturing yield can be increased.

As described above, the chip component transfer method according to the present invention is applied to the display device manufacturing method according to the present embodiment. The transfer method of the chip component according to this embodiment is as follows.

(Method for relocating chip components)
The chip component transfer method according to the present embodiment includes a first substrate on which chip components constituting pixels are arranged, and a radiation-sensitive composition containing a compound having a polymerizable group and a radical polymerization initiator. comprising a second substrate having an organic layer;
a step of contacting the chip component on the first substrate and an organic layer on the second substrate and bonding them by exposure; separating the chip component from the first substrate and transferring the chip component to the second substrate;
a third substrate having one or more electrodes and a conductive layer formed over the electrodes;
contacting and heating the chip component on the second substrate and the conductive layer of the third substrate;
A method of transferring a chip component, comprising: separating the second substrate and the third substrate and transferring the chip component to the third substrate.

The method of transferring chip components according to the present embodiment is not limited to light-emitting elements constituting pixels of a display device as chip components, and can also be applied to substrate mounting of various semiconductor chips.

[Other embodiments]
Although the embodiments have been described above, it should not be understood that the statements and drawings forming part of the disclosure of these embodiments limit the present invention. Various alternative embodiments, examples and operational techniques will become apparent to those skilled in the art from this disclosure.

For example, in the manufacturing method of the display device according to the above-described embodiment, the layout area of the chip components 2 on the temporary substrate 1 is set to have the same vertical and horizontal dimensions as the display area of the micro LED display. Therefore, a large number of chip components 2 that constitute all the pixels can be collectively transferred. However, in the manufacturing method of the display device according to the present invention, the chip components 3 may be transferred to the display area of the TFT substrate 6 using a plurality of transfer substrates 5 . That is, if the display area of the TFT substrate 6 can be covered by the chip components 3 using a plurality of transfer substrates 5, the transfer substrate 5 does not have to be one.

In the manufacturing method of the display device according to the above embodiment, the TFT substrate 6 can be provided with an anisotropic conductive film. good too. When the protective resin layer is laminated, when the transfer substrate of the second substrate and the TFT substrate of the third substrate are superimposed and thermocompressed, the protective resin layer covers the lower surface of the chip component, so that the wiring part of the chip component and the chip are damaged. This has the effect of suppressing deterioration of the wiring portion of the component.

A radiation-sensitive composition has a compound having a polymerizable group. Synthesis examples of the compounds are shown below.

<Synthesis of a compound having a polymerizable group>
41.08 parts by mass of 2,5-dimethylhexane-2,5-diyl diacrylate (manufactured by Osaka Organic Co., Ltd.), 11.18 parts by mass of diisopropylamine, and 150 parts by mass of tetrahydrofuran were placed in a flask equipped with a condenser and a stirrer. The mass part was charged. In this solution, 1,3,4,6-tetrakis(2-mercaptoethyl)tetrahydroimidazo[4,5-d]imidazole-2,5(1H,3H)-dione (Shikoku Kasei Co., Ltd. TS-G ) dissolved in 90 parts by mass of tetrahydrofuran was added dropwise at room temperature, and after the dropwise addition was completed, the mixture was heated to 30°C and stirred while maintaining this temperature for 7 hours.

The viscous liquid obtained by concentrating the reaction solution under reduced pressure and distilling off the solvent was placed on silica gel. -Dimethylhexane-2,5-diyl diacrylate was removed. Thereafter, ethyl acetate was passed over the silica gel, and the eluted ethyl acetate solution was taken out. Ethyl acetate was concentrated under reduced pressure, distilled off, and dried under reduced pressure to obtain 36 parts by mass of the target compound represented by the following formula (9).
2,5-dimethylhexane-2,5-diyl diacrylate

ただし、上記式（９）中のＲは、下記式（１０）で示される構造である。

However, R in the above formula (9) is a structure represented by the following formula (10).

<Preparation example of radiation-sensitive composition>
100 parts by mass of the target compound represented by the above formula, 10 parts by mass of N-trifluoromethyl-1,8-naphthalimide (manufactured by ADEKA) as an acid generator, and BASF, IrgOXE-03) as a photoinitiator. A radiation-sensitive composition was prepared by adding 2 parts by mass and 3 parts by mass of KAYAMER PM-21 (manufactured by Nippon Kayaku Co., Ltd., 2-methacryloyloxyethylcaproate acid phosphate) and heating.

<Evaluation of photocuring adhesion of radiation-sensitive adhesive>
A 76 mm long, 26 mm wide, and 1.0 mm thick glass slide (Muto Pure Chemicals) was washed with an alkaline detergent, water, and 2-propanol in that order, and dried. The washed substrate was treated with a UV/ozone surface treatment apparatus (manufactured by Sen Engineering) immediately before use. A cross-shaped test piece was prepared by applying a load of 4.9 Newtons for 15 minutes to the laminated glass plates sandwiching the adhesive composition (1). This test piece was passed through a UV conveyor (manufactured by Eye Graphics) equipped with a metal halide lamp and irradiated with light. Using a universal testing machine EZ-LX manufactured by Shimadzu Corporation, the adhesive strength of the test piece after light irradiation and curing was measured.

<Comparing the adhesion of the test piece after photocuring and after heat treatment>
A test piece was prepared in the same manner as in the photocuring adhesion evaluation described above.
With respect to the prepared substrate, the adhesion strength of a test piece after photocuring and a test piece that was further heat-treated on a hot plate at 120° C. for 3 minutes after photocuring was measured. The results are shown in FIG.
The adhesive strength of the test piece heat-treated for 3 minutes on a hot plate at 120° C. after photocuring decreased by 40% or more relative to the adhesive strength of the test piece after photocuring. It is believed that part of the polymer forming the organic layer by the heat treatment was decomposed by the acid generated from the thermal acid generator, and the crosslinked structure was significantly changed, resulting in a significant decrease in adhesiveness.

After photocuring, the test piece was further heat-treated on a hot plate at 120 ° C. for 3 minutes. After washing and drying, the transmittance of the test piece was measured using an ultraviolet spectrophotometer.
The transmittance of the virgin test piece with a wavelength of 400 nanometers was 90.0%, while the transmittance of the test piece after treatment with the TMAH aqueous solution was 89.3%. It was found that the compound after decomposition of the organic layer can be easily removed by performing treatment with an aqueous TMAH solution.

As described above, according to the manufacturing method of the display device according to the present invention, it has been found that minute parts such as chip parts can be adhered by simple exposure, and can be easily detached by heat treatment.

1 First substrate (temporary substrate)
2 chip component 3 organic layer 4 second substrate (transfer substrate)
5 Third substrate (drive circuit substrate)
6 electrode 7 conductive layer 8 organic layer with reduced adhesion

Claims (8)

A first substrate on which chip parts constituting pixels are arranged, and a second substrate having an organic layer formed of a radiation-sensitive composition containing a compound having a polymerizable group and a radical polymerization initiator,
a step of contacting the chip component on the first substrate and an organic layer on the second substrate and bonding them by exposure; separating the chip component from the first substrate and transferring the chip component to the second substrate;
a third substrate having one or more electrodes and a conductive layer formed over the electrodes;
contacting and heating the chip component on the second substrate and the conductive layer of the third substrate;
separating the second substrate and the third substrate and transferring the chip component to the third substrate;
A method of manufacturing a display device comprising: 2. The method of manufacturing a display device according to claim 1, wherein the compound having a polymerizable group is a compound having a structural site represented by the following formula (1).

(In formula (1), R ^a represents a hydrogen atom or a methyl group. R ^b to R ^e each independently represent a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, represents an alkyl halide having 1 to 12 carbon atoms, n is an integer of 1 to 12. * represents a bonding position.) 3. The method of manufacturing a display device according to claim 1, wherein the content of the organic solvent contained in the radiation-sensitive composition is 3% by mass or less. 4. The method of manufacturing a display device according to claim 1, wherein said chip component is a micro LED chip. 5. The method of manufacturing a display device according to claim 1, wherein the conductive layer is a layer formed of an anisotropically conductive film. A first substrate on which chip parts constituting pixels are arranged, and a second substrate having an organic layer formed of a radiation-sensitive composition containing a compound having a polymerizable group and a radical polymerization initiator,
a step of contacting the chip component on the first substrate and an organic layer on the second substrate and bonding them by exposure; separating the chip component from the first substrate and transferring the chip component to the second substrate;
a third substrate having one or more electrodes and a conductive layer formed over the electrodes;
contacting and heating the chip component on the second substrate and the conductive layer of the third substrate;
separating the second substrate and the third substrate and transferring the chip component to the third substrate;
A chip component transfer method comprising: 7. The method of transferring chip parts according to claim 6, wherein the organic layer formed from the radiation-sensitive composition is adhered to the chip part by exposure, and the organic layer is thermally decomposed by heating. A radiation-sensitive composition comprising a compound having a polymerizable group represented by the following formula (1), a radical polymerization initiator, and a thermal acid generator.

(In formula (1), R ^a represents a hydrogen atom or a methyl group. R ^b to R ^e each independently represent a hydrogen atom, a hydrocarbon group having 1 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, represents an alkyl halide having 1 to 12 carbon atoms, n is an integer of 1 to 12. * represents a bonding position.)

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